Threatened species are any species (including animals, plants, fungi, etc.) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterized by the population dynamics measure of critical depensation, a mathematical measure of biomass related to population growth rate. The International Union for Conservation of Nature (IUCN) is the foremost authority on threatened species, and treats threatened species not as a single category, but as a group of three categories i.e. Critically Endangered, Endangered or Vulnerable, depending on the degree to which they are threatened. As per Section 38 of the Biological Diversity Act, The Ministry of Environment & Forests and Climate Change, Govt. of India in consultation with the Govt. of Himachal Pradesh, has notified eight species of plants and ten species of animals which are on the verge of extinction in the Gazette notification dated 17th March, 2009.